Traditional precast has been around since the beginning of time and pretty much emulates early cut stone. Where the Eqyptians had to cut, grind and polish their rock to make their architectural elements, today, with the ease of mixing portland cement and aggregates, we can pour it into molds preshaped for the job. Way easier now but the outcome is virtually the same look and feel - still hard as stone and just as heavy. Although with different formulas and design mixes you can adjust its weight a bit. The end result is a product that will last.